Fast defluorination and removal of norfloxacin by alginate/Fe@Fe3O4 core/shell structured nanoparticles

► Robust, thermo-stable, and environmental friendly Fe3O4@ALG/Fe are prepared. ► Norfloxacin is efficiently degraded in Fenton-like process based on Fe3O4@ALG/Fe. ► The fluorine element in norfloxacin changes into F− ions within 1 min. ► 100% norfloxacin and 90% of TOC is removed within 60 min. ► Catalyst with adsorbed intermediate is collected under an external magnetic field.